IDEAS home Printed from https://ideas.repec.org/a/gam/jagris/v14y2024i12p2283-d1542751.html
   My bibliography  Save this article

Characterization of In Situ Ruminal Degradation of Crude Protein and Individual Amino Acids from Ryegrass

Author

Listed:
  • Álvaro G. Morales

    (Instituto de Ciencia Animal, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia P.O. Box 567, Chile
    School of Animal Sciences, Virginia Tech, Blacksburg, VA 24061, USA
    This paper is a part of the Ph.D. Thesis of Álvaro G. Morales, presented at Virginia Tech University (USA).)

  • Álvaro R. Navarro

    (Instituto de Ciencia Animal, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia P.O. Box 567, Chile)

  • Rubén G. Pulido

    (Instituto de Ciencia Animal, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia P.O. Box 567, Chile)

  • Mark D. Hanigan

    (School of Animal Sciences, Virginia Tech, Blacksburg, VA 24061, USA)

Abstract

In temperate pasture-based dairy systems, ryegrass ( Lolium perenne L.) is a key forage due to its high crude protein (CP) content, yet its rapid ruminal degradation could limit the supply of rumen-undegraded protein and essential amino acids (EAAs) to dairy cows. This study aimed to investigate the in situ ruminal degradability of CP and individual amino acids (AAs) in fresh ryegrass at the vegetative stage. Three second-parity, rumen-cannulated Holstein Friesian cows (487 kg body weight, 16.5 kg milk/day) were used for the incubation of ryegrass samples collected in different seasons at the vegetative stage. The degradation kinetics were assessed using the Ørskov and McDonald model, with mathematical corrections for microbial contamination. Results showed that the effective degradability (ED) of AAs was generally higher than that of CP ( p < 0.05), exceeding 2%, and that some EAAs, particularly lysine, exhibited an ED up to 5.5% greater than CP ( p < 0.05). These differences underscore the need for caution when using CP as a proxy for AA degradation in dietary formulations. Given the high degradability of ryegrass AAs, it would be important to monitor and adjust their supply in diets with high ryegrass inclusion to prevent potential deficiencies that could impair milk production and reduce feed efficiency.

Suggested Citation

  • Álvaro G. Morales & Álvaro R. Navarro & Rubén G. Pulido & Mark D. Hanigan, 2024. "Characterization of In Situ Ruminal Degradation of Crude Protein and Individual Amino Acids from Ryegrass," Agriculture, MDPI, vol. 14(12), pages 1-15, December.
    • Handle: RePEc:gam:jagris:v:14:y:2024:i:12:p:2283-:d:1542751
    as

    Download full text from publisher

    File URL: https://www.mdpi.com/2077-0472/14/12/2283/pdf
    Download Restriction: no
    File URL: https://www.mdpi.com/2077-0472/14/12/2283/
    Download Restriction: no
    ---><---

    Corrections

    All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:gam:jagris:v:14:y:2024:i:12:p:2283-:d:1542751. See general information about how to correct material in RePEc.

    If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

    We have no bibliographic references for this item. You can help adding them by using this form .

    If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: MDPI Indexing Manager (email available below). General contact details of provider: https://www.mdpi.com .

    Please note that corrections may take a couple of weeks to filter through the various RePEc services.

    IDEAS is a RePEc service. RePEc uses bibliographic data supplied by the respective publishers.